1. Field of the Art
The present invention relates to a timer circuit used for controlling a write and erase time of E.sup.2 PROM (Electrical Erasable Programmable Read Only Memory), etc.
2. Prior Art
Hitherto, there has been proposed a timer circuit used for a write and erase time control of a semiconductor memory, wherein its timer operation is performed by transferring a charge stored in a charge storage capacitor to a charge pump capacitor through a first transfer gate thereafter to repeatedly effect a discharge operation by using a second transfer gate, thus gradually lessening the charge in the charge storage capacitor.
However, the drawback with the above-mentioned conventional timer circuit is that a large capacity ratio of the timer is required for assuring a prolonged operation time, resulting in enlargement of LSI.